Regulator



21 v l l Aug. 7, 1945. j D; @EGG 12538-1546 REGULATOR .original Eiledmeg, 1941 s sheets-sheet;

D. GREGG REGULATOR Aug. 7, 1945.

Original Filed Dec. 6, 1941 3 Sheets-Sheet 2 Aug.; 1945, D. GREG@ 2,381,346

, REGULATOR Original Filed Deze. 6, i941 3 Sheets-Sheet 3 mostatic flow control unit of the present invention.

' same unit.

. Patented Aug.; 1945 REGULATR David Gregg, Caldwell, N. J., .assigner to Bendix Aviation Corporation, South B end, Ind., a corporation of Delaware Original application December 6, 1941, Serial No. 421,979, nowPatent No. 2,316,417, dated April 13, 1943. Divided and this application September 18, 1942, Serial No. 458,879l

2 claims. (o1. 1374-139.)

This invention relates to heating systems, and more vparticularly to 'thermostatic control means for heating systems intended for heating aircraft cabins. l

' Aircraft cabin heating systems in' use today are usually of the steam type, wherein a flash boiler situated in the engineexhauststack is employed as the steam lgenerating unit for a system including a steamradiator disposed in the air intake conduit of the craft. One of the serious 4vproblems encounteredin heating cabins is that of obtaining even Aand uniform heat control throughout the cabin under a wide range of external air temperatures, and the conventional systems have failed to effect suitableheat.controlrequired for lm'odern transports.

Itis an object of the present invention to proy A to minimize the temperature change through ,which the vairwneed be raised upon a demand for V,fit is, another object of the invention to includev vthe provision of a novel thermostatic control device for regulating the flow of fluid to a boiler or other heat generating device. ,Qther objects will appear froml a study of the following specification-when made in conjunction with the 4attached drawings, throughout which like 4numeralsI designate like parts.

Fig. l is a schematic diagram of a steamheating system showing the use of the novel thermoy'static regulating valve of the present invention. Fig. 2 is a longitudinal, vsectional View ofa thering the' flow'regulating valve of the present invention is set forth in Fig. 1. This system is fully described andclaimed in the application of David Gregg, Serial No. 421,979, filed December 6, 1941, now U. s. Patent No. 2,316,417, dated'April 13, 1943,4ofwhich thepresent application is a division. A Water `supply tank I6 is connected by a Water `pi pe |1 to a boiler feed pump I8 `of conventionaldesign, the output of which is connected lthrough another-water pipe I 9 to two parallel branches including first, a Water conduit 20, a thermostatic iiovvy control element 2| having a ,thermal transfer head' 22 projecting into cabin I0', and a fwater delivery pipe 23, which is con- 'nected to the input'` of the flash boiler 24 by means of a conduit 25. The second branch includes a water supply pipe 26 connected to, another thermostatic flow control device 21 having a thermal transfer head 28, the output of which is connected, by means of a `Water'delivery pipev 29, to conduit 725 and boiler 24. Boiler 24 is contained in the Vexhaust' stack 3D of an aircraft engine (notshown) `and the output of flashboiler 24. communicates' with' a steam radiator 3l througha steam pipe 32.

`The:therrx'lostats or thermostatic flow control devices 2l and 21, Will be explained `in detail below, but primarily, their function is to permit water VKto 110W, through their respective branches into the 'boiler 24 until a particular temperature for the surrounding air has been attained, upon which Water flow through one or both of the lbranches .may be stopped.

' Water tank I6 may be provided with a pressure relief. valve f33 of any conventional design in order to-prevent the possibility of destruction of the tank by.high.steam pressure, and with a vacl uum valve 34ofany conventional design, which Fig. 3 isa cross-sectional view of theunit shown in Fig. 2, taken along the line 3-3 of Fig. 2.

Fig. 4 is aside elevation of the unit shown in Fig. 2; and

f Fig. 5 is a front oryend elevational View of the Having reference to Fig. l, there is shown an aircraft cabin I0, into which open a plurality of .vents II of an airduct I2, havingbranch mem- -a bers I3. A ir from the atmosphere is received through a duct I4 containing an enlarged' por'- -tion I5,v which in turn is connected directly to serves to `prevent the formation of low pressures Within tank I6 upon condensation of. steam therein'.A

Water-fromltank I6 is pumped through the v.boiler yfeed pump I8,`through the branch pipes 20Y and 2E, .then through the branch delivery is formed, Which Will flow into radiator 3| and heat the surrounding air, after which, steam o1' condensed steam returns to Water supply tank yIii-.by way of a return conduit 35.

, Under. certain conditions ofr operation, both flow .control elements 2l .and 21 will cut off flow to fischer-.25, and since boiler feed pump is intended-to operate continuously, a by-pass conduit. 36 is Vprovided to prevent excessive pressures lfrom building .up when W through control elements 2| and 21 is stopped. A relief valve 31 is connected to the 'by-pass conduit 36 to permit return of water automatically from water pipe I9 back to the input of pump I8 when the pressure due to the cut-01T of fluid flow through both branches 2|)y and 26 becomesexcessive.

The particular cabin temperature desired may be selected and maintained in the manner to be described later, and for the purposes of explanation of the invention, we may assume that it isl desired to maintain a temperature of '10 degrees F. within cabin I9. The entering air may be on the order `of Zero degrees F., and will be heated upon contact with radiator 3|. It is proposed that water shall be fed to the boiler 24 through the thermostatic control device 21 independently of water flowing through the thermostatic control device 2I, until the temperature `of the air passing by the thermal transfer head 28 shall be equal to the temperature desired within cabin I0. In this case, We will assume that control device 21 yacts to stop 4flow of water therethrough when the air passing through conduit I2 adjacent the head 28 is 70 degrees.

` Air entering the cabin at '70 degrees will be too cool to ymaintain the cabin temperature at 70 .degrees under normal conditions., `and therefore, the thermostatic control device 2| will permit Water to be delivered therethrough to boiler 24 until the air adjacent the thermostatic head -28 shall attain the temperatureof 70 degrees. Prior to the cut-off of waterl ow through thermostatic-control device 21-that is, prior to the attaining of "I` degrees F. in the neighborhood of thermo-transfer head 28, water will be .flowing to boiler 24 through both parallel branches passing through control devices 2| and 21.` vThe capacity of boiler-24 is such that it can lreadily convert water that is fed` tov it through both branches into steam. Therefore, the cold air entering conduit I4 will be, warmed rather readily, and once it has been warmed to 70 degrees, the volumeof steam necessary to increase the temperature of the air owing into cabin I0 through vents `I I, in order to maintain 70 degrees in cabin II), need be only that amount supplied through the thermostatic flow control element 2|.

A knob 39 projects from the casing of thermostat 2|, and, as Will be described below, the cabin temperature at which vwater is tobe cut off through thermostat 2|, may be selected through a suitable setting of the knob. A similar knob 40 is carried on a shaft l4I projecting through the casing of thermostat 21 and also to a point outside the air duct I4.

The thermostatic control devices 2| and 21 .may incorporate identical thermo-sensitive and regulating valve structure, and therefore, Ain Figs. 2 to 5, the description of these parts of the thermostatic control device 2| is applicable toV device 21.

Housing 38 has an open end f1tted with a closure plate 42, which is held in gas-tight engagement with housing 3| by means of a plurality of screw-studs 43.) This housing also has a screw-threaded aperture 44, which carries a gland nut 45, having an integral extension forming the thermo-transfer head 22,. This head carries a seriesof heat radiating ns 46 exteriorly of a cylindrical chamber 41. A flexible metallic bellows or sylphon 48 has one end welded or brazed to a metallic collar 49 fitted tightly Within gland nut '45, which has one end welded to gland nut 45 at point 5D. The other end of flexible bellows vt8 has a Vgas-tight` connection with the flatend face of a plunger 52. The outermost end of chamber 41 is formed into a screw-threaded boss 53, upon which is carried a screw-threaded cap 54, which ts upon boss 53 with a gastight connection. It will thus be seen that chamber 41 is a gas-tight chamber of variable volume .by virtue of the flexible bellows 48. A quantity of air or any other gas, or a liquid such as alcohol, carbon tetrachloride, or the like, is allowed to ilow through screw-threaded boss 53 prior to the application of cap 54, and thus, the uid Within chamber 41.may be at any desired pressure.

lPlunger 52 extends within housing 38 and carries at its end a knife edged bearing point 55,Which rests against one end 56 o`f a loose link 51, contacting, at its other end 58, with a valve rod 59. Valve rod 59 extends within a valve chamber 6|), which has transverse openings 6I and 62 opening thereinto and aligned with each other. A piston valve 63 is carried on valve .rod 59, and in the position shown in Fig. 2, it closes off communication between transverse openings" `BI and |52,v but when moved to to return valve `63? to the closed position shown runder conditions to be later described. A pin 64 on valve 63y serves as a guide and centering means for spring |55.v

i Link 51 is pvoted, :by-means of a pin member r66, to the parallel arms 61 of a bracket member w68.' The horizontally disposed portion of bracket 68', `as viewed in Fig.` 2, is a, hollow vcylindrical member 69 confined within a `cylindrical casing .1.9, having an inwardly extending flange 1| at its right end, and enlarged bossvportion 89 at its left end, forming an integral `end'wall of housing 38. A lpiston 12 is confined within cylindrical casing 10 and is slidable therein,` and is retained von cylindrical portion 69 of ybracket 68 yby means of a conventionalV retaining ring 13.

A helical spring 14 has one end bearing against inwardly directed flange 1|, and itsA other end bearing against the inner face of Apiston 12. ,Actienof .spring 14 is `such, that they end face of bracket 6B is rurged to the left against the .cam face 16 of a cylindrical cam member 11. Cam member 11 carries a stub shaft 18, which is. borne within an aperture 19 formed -n the toward the left end thereof, which open into valve -chamber 66, which also has an opening 83 formed below valve chamber 60, and into which 'is .fitted a screw-threaded pipe connecting member 84 carrying adrain pipe 85.

The front or manual control end of vflow control element 2|` is shown in Fig. 5. An arcuate scale member 86 is shown disposed above the index end of knob 39, and this scale bears indicia of a temperature ran-ge through which. the thermostat is designed to .exert control. It will be understood that the knob 39 is readily accessible to the steward or ,any person, in the vcabin. IIB `who desires to `set the thermostat for a particular cabin temperature. l The knob 49 of thermostat 21, which perfo-rms the same lfunction as does knob 39, "will ordinarily be accessible for periodic adjustment by a crew member, so' that the temperature of entering air may be regulated by a flight or maintenance crew member, altho-ugh it is intended that thermostat 21 be set before a particular flight to a fixed cut-off temperature, and not -be adjusted during flight.

It is believed that the operation of the system of Fig. 1 will be clear from the above description, and the operation of thermostats 2l and 21 to control the flow of water to boiler 24 will be fully understood from the above description, taken with the following explanation, particular reference being made to Figs. 2 and 3:

The volume of chamber 41 depends upon the temperature of ther fluid therein, which, oi' course, is a function of the temperature of the air surrounding the heat transfer head 22. As the temperature local to head 22 increases, the volume ofl chamber 41 'will become greater due to the .increased pressure of the fluid contained therein, and plunger 52 will be moved to the right. Upon a lowering of thel temperature about head 22, the fluid within chamber 41 will become cool,V the volume of chamber 41 will therefore become less, and plunger 52 will move to the left. The fins 46 aid in the rapid transfer of heat. to chamber41 from the surrounding air or from chamber 41 to the surrounding air, depending upon the direction of temperature change.

Assuming that knob 39 has been set for a cutoff temperature of 70 degrees F., and that the air surrounding head 22 is at less than this temperature, then plunger 52 is retracted somewhat into chamber 41, and the thermostatic control device is so designed that in this retracted position of plunger 52, spring member 65 forces valve 63 to the right of the position shown, and thus, through the movement of valve rod 59 to the right, the upper end 56 of link 51 will move counter-clockwiseabout the pivot pin 66.- Flow of water intovalve `chamber 60 through opening 6l, and from chamber 60 and opening 62 through delivery pipe 23 will be established. Of course,

vas the water'thus flows through thermostat 2|,

it is delivered to create steam in the boiler 24, and thus, the temperature of air adjacent the heat transfer head 22 increases. As the gas pressure in chamber 41 increases with temperature,

the plunger 52 is moved progressively to the right, and when the selected cabin temperature has been attained, valve 63 will have been forced by the right-hand movement of plunger 52, as transmitted through link 51 and valve rod 59, to close transverse openings 6I and 62, and thus, stop flow of water through thermostat 2l.

With cabin temperature at 70 degrees, and thermostat 2l in its cut-off condition, as shown in Fig. 2, if the control knob 39 is moved to maintain a lower cabin temperature, for example 65 degrees, then cam face 16 presents a contact point'of less axial projection to end face 15, and spring 14 forces piston 12 and bracket 68 to the' left. Since the position of plunger 52, and therefore, bearing point 55, is fixed by the temperature Within'chamber 41, translation of bracket 68 to the'left will cause the end 58 of link 51 to force vvalve rodl 59 further to the left, and of course,

this movement merely continues to keep openijngs 6I land 62 out of communication, so that water flow is prohibited. The temperature about head |22 will continue to decrease, and the gas in chamber 41. will gradually cool, allowing plum;-

er 52 to be retractedl into chamber 41. Thisretraction moves bearing point 55 to the left, and spring 65 acts to rotate link 51 counter-clockwise about pin 66 until the air about head 22 falls to 65 degrees temperature, at which point valve 63 has moved to the right sufciently to establish water flow through openings 6I and 62, and water is then fed to boiler 24. The resultant steam raises the temperature about head 22, and at 65 degrees, plunger 52 has traveled to the right sufliciently to again move valve 63 to cutoff position, thus stopping the vformation of steam and the further rise of temperature in cabin 10.

It will be seen that thermostatic control device 2l thus acts to maintain a predetermined temperature in cabin I0, and that the flow of Water to boiler 24 is permitted only when heat is demanded to raise the cabin temperature to its desired level. 'Small amounts of water that may settle in the chamber El] are carried back to tank I6, or are otherwise disposed of through the drain pipe 85.

While only one embodiment of the present invention has been shown in the drawings, it is to be understood that various changes may be made Without departing from the scope of the present invention. For this reason, it is intended not to limit the invention by the description herein given as an example, but solely by the scope of the appended claims.

What is claimed is:

l. Aiiow control device comprising a housing, a plunger within said housing, a bracket within said housing, a cylindrical casing surrounding a portion of said bracket, va piston carried on one end of said bracket within said cylindrical casing, a cam having engagement with the end surface only of saidA bracket, a spring within said casing bearing against said` piston and urging said piston and bracket toward said cam, la flow control valve within said housing, means for urging said valve into open position, a link pivoted to said bracketntermediately of its ends,l one end of said link being in engagement with said plunger and the other end of said link beingv in engagement with a valve rod connected to said valve and means for adjusting said cam to translate said bracket and link to modify the control of said plunger on said valve `through said link and valve rod.

2. 1n a 110Wk Vcontrol device, a housing, af

,tivev for shifting said rst member to establish an effective operating range for said operating means to enable the latter to render said valve effective in conformity to the position of the cam,

4resilient, means within `said housing effective for maintaining said members in engagement with said cam andsaid element respectively and said element in engagement with said operating means at all times to effect positive shifting of said members upon operation of said cam.

. DAVID GREGG. 

